Leo Triplet

Messier 65 (NGC 3623) is a spiral galaxy of type Sa in the constellation Leo, lying approximately 35 million light-years from Earth. It was discovered by Charles Messier on March 1, 1780. NGC 3623 is one member of the famous Leo Triplet — a visually striking group of three galaxies that can be seen in the same binocular or telescope field: M65 and M66 (NGC 3627) are separated by only about 20 arcminutes on the sky, with the larger and face-on NGC 3628 just half a degree to the north. All three galaxies are physically associated and lie at similar distances, bound in a loose gravitational group.

NGC 3623 is an early-type Sa spiral, meaning it has tightly wound, relatively faint spiral arms and a large, prominent central bulge — the opposite end of the spectrum from the loosely wound, arm-dominated Sc and Sd spirals. It is tilted at a steep angle to our line of sight, presenting an elongated, edge-on-ish view that reveals its prominent dust lane along the disk. M65 appears relatively undisturbed compared with its companion M66, which shows noticeably distorted spiral structure — possibly due to past gravitational interactions with M65 and NGC 3628. M65 has produced no supernovae in the modern observational record, reflecting its relatively quiescent, low-star-formation environment.

In binoculars M65 and M66 appear side by side as two fuzzy ovals in the same field; a small telescope shows both clearly, with M65 appearing more elongated and M66 showing a slightly brighter, more compact nucleus. This image was taken with the WIYN 0.9-meter telescope at Kitt Peak on the night of December 19, 2002.